<!DOCTYPE html>
<html lang="en">
<head>
  <title>BrowserWindow</title>
</head>
<body>
  <h1>Hello from your BrowserWindow!</h1>
  <button id="close-btn">Close this window</button>
  <script>
    const button = document.querySelector('#close-btn')
    button.addEventListener('click', () => window.close())
  </script>
</body>
</html>
